JP2004014178A - Sheet-shaped heater module and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet-shaped heater module well adhering to an object to be heated, with good heating efficiency, without posing any safety problem, and to provide a manufacturing method of the same. <P>SOLUTION: The sheet-shaped heater module is manufactured by arranging wire-shaped or sheet-shaped heaters insulated from each other between thermally fusible resin films forming both sides of lamination body, and laminating a heat-resistant foamed resin heat insulation material at least on the thermally fusible resin film at one side; or manufactured by forming a wire shaped or tape-shaped heater by laminating a metal film on the thermally fusible resin film and forming a circuit on the metal film, and welding the metal film to the thermally fusible resin film with heat and pressure, and laminating a heat-resistant foamed resin heat insulation material at least on the thermally fusible resin film at one side. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
INDUSTRIAL APPLICABILITY The present invention has good adhesion to an object to be heated, can be used at high temperatures, and is suitable for uses such as a heater having good thermal efficiency, particularly for heating and keeping heat for cooking, pipes and hoses. The present invention relates to a sheet heating heater module that can be used for purposes such as heating and heat retention, and a method for producing the same.
[0002]
[Prior art]
Conventionally, to prevent solidification and adhesion of substances to be transported to pipes in analytical instruments such as liquid chromatographs or mass spectrometers and pipes that constitute transport paths for chemicals in semiconductor manufacturing equipment, heat pipes to keep them warm. It is necessary to heat the pipe in order to evaporate the substance adhered to the inner surface and secure the degree of vacuum.
[0003]
In such a case, the nichrome wire is used by being insulated with a heat insulating material such as glass cloth or silicone, but generally used glass cloth has a problem in insulation and is quite bulky. Therefore, the adhesiveness with a heated body such as a pipe is poor. Therefore, thermal efficiency is low and temperature control cannot be performed accurately. Further, the silicone rubber has a use temperature of at most 200 ° C. and is insufficient in heat resistance.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a planar heating heater module having good adhesion to an object to be heated, good thermal efficiency, and no safety problems, and a method for producing the same.
[0005]
[Means for Solving the Problems]
According to the present invention, a linear or tape-like heating element is mutually insulated between a heat-fusible resin film forming one layer of the laminate and a heat-fusible resin film forming the other layer. The present invention relates to a planar heat-generating heat module in which a heat-resistant foamed resin heat insulating material is laminated on at least one side of a heat-fusible resin film.
Also, the present invention provides a method for forming a linear or tape-shaped heating element by laminating a heat-fusible resin film and a metal foil, forming a circuit on the metal foil, and then thermocompression bonding the heat-fusible resin film. Further, the present invention relates to a method for producing a planar heat generating heat module in which a heat-resistant foamed resin heat insulating material is laminated on at least one side of a heat-fusible resin film by thermocompression bonding.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention are listed below.
1) The above-mentioned planar heat generating heater module, wherein the heat-fusible resin film is a polyimide film having a three-layer structure in which a heat-fusible resin layer is laminated on both sides of a highly heat-resistant polyimide layer.
2) The above-mentioned sheet heating heater module wherein the tape-shaped heating element is made of stainless steel foil.
3) The above-mentioned planar heating heater module, wherein the heat-resistant foamed resin insulation material is a foamed polyimide film.
[0007]
4) The above-mentioned sheet heating heater module, wherein the resins used are all made of aromatic polyimide.
5) The above-mentioned planar heat-generating heat module which can be used even at 350 ° C.
6) The above-mentioned sheet heating heater module having flexibility.
7) The above-mentioned sheet heating heater module, wherein the heat-fusible resin film is made of a heat-fusible resin having a glass transition temperature lower than the glass transition temperature of the heat-resistant foamed resin heat insulating material.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the sheet heating heater module of the present invention and a method for manufacturing the same will be described in detail with reference to the drawings. First, a planar heating heater module according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a sheet heating heater module. FIG. 2 is a plan view of an example of the sheet heating heater module of the present invention shown in FIG. FIG. 3 is a plan view of another example of the sheet heating heater module.
[0009]
The heat generating heater module 1 according to the embodiment shown in FIGS. 1 to 3 comprises a heat-fusible resin film 2 forming one layer of the laminate and a heat-fusible resin film forming the other layer. A linear or tape-shaped heating element 3 is disposed between the film 4 and the heating element 3 so as to be insulated from each other, and a heat-resistant foamed resin heat insulating material 5 is laminated on at least one side of the heat-fusible resin film 4. .
As shown in FIGS. 2 and 3 as an embodiment, the sheet heating heater module 1 is usually used with a terminal provided at an end of a tape-shaped heating element 3.
[0010]
The heat-fusible resin film in the present invention may be a single heat-fusible resin film or a two- or three-layer structure [heat-fusible resin layer / high heat-resistant resin layer (/ heat-fusible resin layer). Heat-fusible resin film), but preferably a heat-fusible resin film having a two- or three-layer structure, particularly a heat-fusible multilayer polyimide film.
The heat-fusible resin film of the present invention has a four-layer structure [heat-fusible resin layer / high heat-resistant resin layer / heat-fusible resin layer / protective film (= high heat-resistant resin layer)]. Heat-fusible resin film of
[0011]
The heat-fusible multilayer polyimide film is, for example, a polyimide precursor solution for providing a heat-fusible polyimide film, preferably a heat-fusible aromatic polyimide on at least one surface, preferably both surfaces of a highly heat-resistant aromatic polyimide layer. It can be obtained by a method of obtaining a polyimide film from a heat-fusible multilayer polyimide precursor (also referred to as polyamic acid) solution that provides a heat-fusible multilayer polyimide film having an aromatic polyimide layer.
[0012]
The high heat-resistant aromatic polyimide in the heat-fusible multilayer polyimide film is preferably 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter simply referred to as s-BPDA). ), Paraphenylenediamine (hereinafter sometimes abbreviated simply as PPD), and optionally 4,4'-diaminodiphenyl ether (hereinafter sometimes simply abbreviated as DADE) and / or pyromellit. It is produced from an acid dianhydride (hereinafter sometimes simply referred to as PMDA). In this case, the PPD / DADE (molar ratio) is preferably from 100/0 to 85/15. Further, s-BPDA / PMDA is preferably 100: 0-50 / 50.
A high heat-resistant aromatic polyimide is produced from pyromellitic dianhydride, paraphenylenediamine and 4,4'-diaminodiphenyl ether. In this case, DADE / PPD (molar ratio) is preferably from 90/10 to 10/90.
[0013]
Furthermore, high heat-resistant aromatic polyimides include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) and paraphenylenediamine (PPD) and 4 , 4'-diaminodiphenyl ether (DADE). In this case, it is preferable that BTDA in the acid dianhydride is 20 to 90 mol%, PMDA is 10 to 80 mol%, PPD in the diamine is 30 to 90 mol%, and DADE is 10 to 70 mol%.
Other kinds of aromatic tetracarboxylic dianhydrides and aromatic diamines such as 4,4'-diaminodiphenylmethane may be used as long as the physical properties of the high heat-resistant aromatic polyimide are not impaired.
Further, a substituent such as a fluorine group, a hydroxyl group, a methyl group or a methoxy group may be introduced into the aromatic ring of the aromatic tetracarboxylic dianhydride or the aromatic diamine.
Any high heat-resistant aromatic polyimide preferably has no glass transition temperature or is higher than 300 ° C.
[0014]
In the synthesis of this highly heat-resistant aromatic polyimide, a solution of polyamic acid which is a random polymerization, a block polymerization, a blend or two or more kinds of imide precursors is synthesized as long as the proportion of each component is within the above range. This is achieved by any method in which a solution of each polyamic acid is mixed and a copolymer is obtained by recombination of the polyamic acids.
[0015]
As the heat-fusible polyimide in the heat-fusible multilayer polyimide film, any thermoplastic polyimide that can be thermocompression-bonded at a temperature of about 300 to 400 ° C. may be used. Preferably, 1,3-bis (4-aminophenoxybenzene) (hereinafter sometimes abbreviated as TPER) and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter a- BPDA).
The heat-fusible polyimide is prepared from 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane (DANPG) and 4,4′-oxydiphthalic dianhydride (ODPA). Is done.
Alternatively, it is produced from 4,4′-oxydiphthalic dianhydride (ODPA) and pyromellitic dianhydride and 1,3-bis (4-aminophenoxybenzene).
Alternatively, 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride or 3,3′-diaminobenzophenone and 1,3-bis ( Prepared from 3-aminophenoxy) benzene and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride.
Further, in the tetracarboxylic acid component, 12 to 25 mol% of 100 mol% of pyromellitic dianhydride, 5 to 15 mol% of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, The balance is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 1,3-bis (4-aminophenoxy) benzene as an essential component as a diamine component, and a melting endothermic peak by DSC measurement. Is also suitable.
[0016]
Other tetracarboxylic dianhydrides, for example, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4), as long as the physical properties of the heat-fusible polyimide are not impaired. -Dicarboxyphenyl) propane dianhydride.
Further, other diamines such as 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, and 2,2-diamine may be used as long as the physical properties of the heat-fusible polyimide are not impaired. Bis (4-aminophenyl) propane, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenyl) diphenyl ether, 4,4′-bis (4-aminophenyl ) Diphenylmethane, 4,4'-bis (4-aminophenoxy) diphenyl ether, 4,4'-bis (4-aminophenoxy) diphenylmethane, 2,2-bis [4- (aminophenoxy) phenyl] propane, Flexible aromatic diamines having a plurality of benzene rings such as 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane; Aliphatic diamines such as 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane and 1,12-diaminododecane, bis (3-aminopropyl) tetramethyldisiloxane May be replaced by a diaminodisiloxane.
Dicarboxylic acids, such as phthalic acid and its substitution products, hexahydrophthalic acid and its substitution products, succinic acid and its substitution products, and derivatives thereof, for blocking the amine terminal of the heat-fusible aromatic polyimide. For example, phthalic acid may be used.
[0017]
The heat-fusible polyimide is obtained by mixing the above-mentioned components with each other and optionally another tetracarboxylic dianhydride and another diamine in an organic solvent at a temperature of about 100 ° C. or less, particularly at a temperature of 20 to 60 ° C. The reaction is carried out to form a polyamic acid solution, and this polyamic acid solution can be used as a dope solution.
In order to obtain the heat-fusible polyimide in the present invention, the amount of the total moles of the acid (as the total moles of tetraacid dianhydride and dicarboxylic acid) in the organic solvent is diamine (as the number of moles). Is preferably 0.92 to 1.1, particularly 0.98 to 1.1, and especially 0.99 to 1.1, and the amount of dicarboxylic acid used is less than that of tetracarboxylic dianhydride. The ratio to the molar amount is preferably 0.00 to 0.1, particularly preferably 0.02 to 0.06.
[0018]
For the purpose of limiting the gelling of the polyamic acid, a phosphorus-based stabilizer such as triphenyl phosphite, triphenyl phosphate or the like is used in an amount of 0.01 to 1% based on the solid content (polymer) concentration at the time of polyamic acid polymerization. Can be added. Further, a basic organic compound-based catalyst can be added to the dope solution for the purpose of accelerating imidization. For example, imidazole, 2-imidazole, 1,2-dimethylimidazole, 2-phenylimidazole, or the like is used in an amount of 0.01 to 20% by weight, especially 0.5% by weight based on polyamic acid (solid content). It can be used in a proportion of up to 10% by weight. These are used to form a polyimide film at a relatively low temperature and to prevent imidization from becoming insufficient.
For the purpose of stabilizing the adhesive strength, an organic aluminum compound, an inorganic aluminum compound or an organic tin compound may be added to the heat-fusible aromatic polyimide raw material dope. For example, aluminum hydroxide, aluminum triacetylacetonate or the like can be added to the polyamic acid (solid content) at a rate of 1 ppm or more, particularly 1 to 1000 ppm, as aluminum metal.
[0019]
The organic solvent used for the production of the polyamic acid includes N-methyl-2-pyrrolidone, N, N-dimethylformamide, and N-methyl-2-pyrrolidone, for both high heat-resistant aromatic polyimide and heat-fusible aromatic polyimide. N, N-dimethylacetamide, N, N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam, cresols and the like. These organic solvents may be used alone or in combination of two or more.
[0020]
In the co-extrusion-casting film forming method, for example, co-extrusion of a heat-fusible aromatic polyimide precursor solution on one or both sides of the high heat-resistant aromatic polyimide polyamic acid solution, It is preferably cast onto a support such as a stainless steel mirror surface or a belt surface to be in a semi-cured state at 100 to 300 ° C. or a dried state before that. The semi-cured state or a state before that means that it is in a self-supporting state by heating and / or chemical imidization.
The co-extrusion is carried out by supplying a two- or three-layer die for extrusion molding by a co-extrusion method described in, for example, JP-A-3-180343 (Japanese Patent Publication No. Hei 7-102661). You can cast it.
On one or both sides of the extruded material layer providing the high heat-resistant aromatic polyimide, a polyamic acid solution providing the heat-fusible aromatic polyimide is laminated to form a multilayer film, dried, and then heated and melted. Heating to a temperature below the temperature at which degradation occurs above the glass transition temperature (Tg) of the adhesive polyimide, preferably 300 to 400 ° C. (surface temperature measured with a surface thermometer) (preferably A heat-fusible multilayer polyimide film having a heat-fusible aromatic polyimide on one or both sides of a high heat-resistant (substrate layer) aromatic polyimide which is dried and imidized by heating at this temperature for 1 to 60 minutes) Get.
[0021]
By using the acid component and the diamine component, the heat-fusible aromatic polyimide has a glass transition temperature of 180 to 275 ° C, particularly 200 to 275 ° C, and preferably has the above-described condition. The non-liquefied and unstretched modulus of elasticity at a temperature in the range of not less than the glass transition temperature and not more than 300 ° C obtained by substantially not causing gelation of the heat-fusible polyimide by drying and imidizing at the temperature. However, it is usually preferable that the elastic modulus at 275 ° C. is about 0.0002 to 0.2 times the elastic modulus at a temperature around room temperature (50 ° C.).
Such an elastic modulus characteristic is achieved by using the above-mentioned monomer component and forming a film under the above-mentioned conditions.
[0022]
The thickness of the highly heat-resistant (substrate layer) polyimide layer is preferably from 5 to 70 μm, particularly preferably from 5 to 40 μm. If the thickness is less than 5 μm, there is a problem in mechanical strength and dimensional stability of the produced heat-fusible multilayer polyimide film. There is no particular effect even if the thickness is more than 70 μm, which is disadvantageous in increasing the density.
The thickness of the heat-fusible aromatic polyimide layer is preferably 2 to 10 μm, particularly preferably about 2 to 8 μm. If it is less than 2 μm, the adhesive performance is reduced, and if it exceeds 10 μm, it can be used, but there is no particular effect, but rather the heat resistance of the flexible metal foil laminate decreases.
The heat-fusible multilayer polyimide film preferably has a thickness of 7 to 75 μm, particularly preferably 7 to 50 μm. If the thickness is less than 7 μm, it is difficult to handle the produced film, and if the thickness is more than 75 μm, there is no particular effect, which is disadvantageous in increasing the density.
[0023]
According to the co-extrusion-casting film forming method, the high heat-resistant polyimide layer and the heat-fusible polyimide on one or both sides thereof are cured at a relatively low temperature to cause deterioration of the heat-fusible polyimide. This is preferable because imidization and drying of the self-supporting film can be completed without giving good electrical characteristics and adhesive strength.
[0024]
Examples of the linear or tape-shaped heating element used in the present invention include those composed of two or more (usually about 2 to 10) metal wires. The diameter of the metal wire is preferably 10 to 500 μm, particularly preferably 20 to 200 μm. Examples of the tape-shaped heating element in the present invention include a metal foil and a strip-shaped metal, and preferably have a thickness of about 5 to 100 μm and a width of about 0.4 to 40 mm. Examples of the metal forming the metal wire, the metal foil, and the band-shaped metal include those having electric resistance such as stainless steel, nichrome, kanthal, inconel, and cast iron, and particularly have a resistivity of 30 × 10 −6 Ωcm or more. Are preferred. A plurality of the linear or tape-like heating elements are arranged at intervals from each other, and the interval is determined by the width of the heater or the number of the linear or tape-like heating elements. Usually, it is preferably set to be about 1 to 20 mm.
[0025]
In particular, the laminated metal foil is etched by a known etching method, for example, a mask is placed on the metal foil and the metal foil such as stainless steel is etched with a ferrous chloride solution to form a substrate having a metal circuit such as stainless steel. Therefore, it is preferable to dispose a heating element.
[0026]
The heat-resistant foamed resin heat insulating material of the present invention is preferably made of polyimide having a glass transition temperature higher than 300 ° C., and has an expansion ratio of 1.5 to about 180 times (density of 900 to 6 kg / m2). ³ Is equivalent to ), Especially about 1.5 to about 150 times the foamed polyimide film or sheet layer.
[0027]
The above-mentioned foamed polyimide film (or sheet) is preferably made of polyimide having a glass transition temperature higher than 300 ° C., and has an expansion ratio of 20 times or more (density of 67.5 kg / m 2). ³ It corresponds to: ) Is cut into a sheet or compressed by a uniaxial press performed at a temperature of 300 ° C to 450 ° C to increase the expansion ratio to 1.5 to 100 times (density of 900 to 13.5 kg / m ³ Is equivalent to ) Control.
[0028]
As the polyimide for providing the foamed polyimide film (or sheet), an aromatic which has a tetracarboxylic acid component as an essential component and is partially monoesterified and / or diesterified by a lower primary alcohol having 4 or less carbon atoms. A mixture of a tetracarboxylic acid component and an aromatic diamine and a diamine compound containing 0.1 to 10 mol% of a diaminosiloxane in an amine component as an essential component has a total amino group content of about 2: 1 with respect to the tetracarboxylic acid component. It can be obtained by heating a polyimide precursor which is a solid-state monomer salt in which molecules are dispersed in a certain ratio.
[0029]
As the above-mentioned tetracarboxylic acid component, 50 to 100% by mole of 2,3,3 ′, 4′-biphenyltetracarboxylic acid component is tetracarboxylic acid and monocarboxylic acid of lower primary alcohol having 4 or less carbon atoms. And / or a mixture with a diester, wherein at least a part of the tetracarboxylic acid component is esterified.
[0030]
In particular, a half ester of 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated as a-BPDA) and a diamine such as p-phenylenediamine (hereinafter referred to as PPD) And 4,4'-diaminodiphenyl ether (hereinafter sometimes abbreviated as ODA), etc., and a component for uniform foaming, such as diaminodisiloxane and further. If necessary, a composition such as an amine compound having three or more amino groups in a molecule such as tetraaminobiphenyl, for example, an aromatic triamine compound or an aromatic tetraamine compound, becomes a polyimide (which means a high molecular weight imide resin). Esterification solvents by ratio, for example, lower primary alcohols such as methanol, ethanol, n-propanol and n-butanol, preferably The methanol - le or ethanol - and Le and uniform mixing, comprising a first step of dissolving. At this time, the concentration of each component can be up to the solubility limit of diamines and the like, but the amount of nonvolatile components in the total amount is up to about 10% to 50%.
[0031]
In particular, as the acid component, the content of the a-BPDA derivative is preferably 50% or more. As the acid component, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter sometimes abbreviated as s-BPDA) or pyromellitic dianhydride (hereinafter abbreviated as PMDA) Does not foam even when used alone. Therefore, a-BPDA is a main component, and other acid components, for example, s-BPDA, PMDA, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (hereinafter sometimes abbreviated as BTDA). , Bis (3,4-dicarboxyphenyl) ether dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2-bis (2,5-dicarboxyphenyl) propane dianhydride 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) sulfone dianhydride, 1,3-bis (3,4-di Carboxyphenyl) -1 A polyimide obtained by using an aromatic tetracarboxylic dianhydride such as 1,3,3-tetramethyldisiloxane dianhydride in an amount of about 0 to 50 mol% as an auxiliary material in 100 mol% of an acid component. Is used for the purpose of adjusting the Tg, adjusting the expansion ratio (decreases as the amount used increases), and the like. All commonly used acid components can be used as long as the Tg does not change significantly.
[0032]
As the diamine compound mixture, 70 to 99.9 mol% of an aromatic diamine having one or two benzene rings in a molecule, and 0 to 29.9 mol of an amine compound having three or more amino groups in a molecule. %, And 0.1 to 10 mol% of diaminosiloxane are preferred.
An imidization catalyst such as 1,2-dimethylimidazole, benzimidazole, isoquinoline, or substituted pyridine may be added to this mixture.
Further, other known additives such as an inorganic filler, an inorganic or organic pigment, and the like may be added.
[0033]
As the diamine component, it is preferable to use up to a dinuclear diamine as a main component, whereby it becomes easy to achieve Tg300 or more of the foamed polyimide. The polysubstituted amine component is not essential but is preferably included partially in order to prevent shrinkage of foaming at high temperature and to increase foaming strength (hard to break during foaming). Diaminodisiloxane acts as a surfactant, and is required in the range of 0.1 to 10 mol%, preferably 0.2 to 5 mol%, for uniform foaming. If the amount is small, it is difficult to make the foam uniform, and if the amount is large, the Tg decreases and the thermal stability decreases. Even with diaminopolysiloxane, uniformity of foaming can be achieved, but it has a sea-island structure and is easily decomposed at high temperatures, and heat resistance is undesirably reduced.
[0034]
Next, a step of preparing an appropriate green body is performed. For example, compression molding at room temperature, casting to dryness as a slurry solution, and filling in a container inert to microwaves are performed. At this time, the lid does not have to be provided (that is, it is not necessary to completely harden the lid). If the green body is in a substantially uniform state, uniformity during foaming can be achieved.
[0035]
It is then heated, preferably by microwave heating. At this time, it is generally performed at 2.45 GHz. This is based on Japanese domestic law (radio law). It is preferable to use the microwave output per powder weight as a standard. This should be defined by repeated experiments. For example, foaming starts at about 100 g / 1 kW in about 1 minute, and the foaming converges in 2 to 3 minutes. In this state, it is a very brittle foam.
[0036]
The temperature of the molded body is gradually increased from about 200 ° C. by heating with hot air or the like (for a rough guide, a temperature increasing rate of about 100 ° C./10 minutes). The final heating is at a temperature of Tg + α for 5 to 60 minutes, preferably about 10 minutes.
By performing the heating and foaming in each of the above steps, the shape becomes irregular, but a foam having uniform elasticity in a foamed state and excellent in restoring force can be obtained. It can be a member by cutting into an appropriate shape.
[0037]
In the foaming, the solid-state polyimide precursor is preferably heated in two stages: heating for foaming and heating for heat setting (higher molecular weight).
In the above-mentioned method for producing a foamed polyimide, the foaming ratio may be controlled by applying a compressive force by placing a shielding plate through which a gas passes during foaming, thereby simultaneously performing mechanical densification.
Then, it is preferable to perform heating for heat fixing (higher molecular weight) at a temperature equal to or higher than the glass transition temperature (Tg) of the foamed polyimide.
[0038]
The method of manufacturing the sheet heating heater module of the present invention will be described with reference to the case of manufacturing the sheet heating heater module of the embodiment shown in FIGS. 1 and 2 as an example. For example, the sheet heating heater module of the embodiment shown in FIGS. 1 and 2 is formed by laminating a heat-fusible resin film and a metal and then forming a circuit on a metal foil to form a linear or tape. After the heating element is formed into a heat-fusible resin film, it is heat-pressed with the heat-fusible resin film, and a heat-resistant foamed resin heat insulating material is formed on at least one of the heat-fusible resin films, and preferably, a heat-fusible resin film is formed. Laminating by heating and pressing at a temperature higher than the glass transition temperature of the heat-fusible resin, particularly at a temperature higher than the glass transition temperature of the resin by 20 ° C. or more, to produce a sheet-like heat generating heat module. Can be.
[0039]
The sheet heating heater module obtained as described above preferably has an outgas of 1 Pa. L / sec · g or less, and can be used in various fields that require a high level of safety and reliability.
The sheet heating heater module of the present invention may be cut as it is or cut to an appropriate length (in this case, it is necessary to electrically connect one end), for example, as shown in FIG. The terminal can be taken out from one end, and the pipe can be used by tightly covering it.
[0040]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to the following examples.
The methods for measuring physical properties in Examples and Comparative Examples are shown below.
Glass transition temperature: DSC (manufactured by Seiko Electronics Co., Ltd., DSC220C) ₂ Measured in an atmosphere at a heating rate of 20 ° C./min.
Expansion ratio: Calculated from true density / apparent density.
As the true density, a value obtained by preparing a polyimide film having the same composition by an ordinary method and using a density gradient tube was used.
The apparent density was determined by measuring the volume by measuring with a vernier caliper a cube or a square sheet cut, and measuring the mass by a balance, and calculating the mass / volume.
As for the outgas, the value obtained by the temperature rise desorption analysis (TDS method) for each organic member using TDS-1400 (manufactured by Denshi Kagaku Co., Ltd.) by the temperature rise analysis at 100 to 300 ° C. was integrated.
[0041]
In the following description, each abbreviation means the following compound.
a-BPDA: 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride
BTDA: 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride
PPD: p-phenylenediamine
ODA: 4,4'-diaminodiphenyl ether
DADSi: 1,3-bis (3-aminopropyl) tetramethyldisiloxane
DMZ: 1,2-dimethylimidazole
[0042]
Reference Example 1
47.1 g (160 mmol) of a-BPDA, 12.9 g (40 mmol) of BTDA, 75 g of MeOH, and 2.5 g of DMZ as a catalyst were heated and stirred for 60 minutes while refluxing to obtain a homogeneous solution, 21.4 g (198 mmol) of PPD, and 0.5 g of DADSi (2 mmol) and 77.1 g of MeOH were added to make a homogeneous solution, concentrated, and dried using a 40 ° C. vacuum dryer to obtain a solid. Furthermore, this solid was ground using a mortar to obtain a raw material powder.
The raw material powder as a solid is compression molded at room temperature by a compression molding machine using a 5 mm spacer, and the molded body is 3,000 W for 5 minutes using a microwave oven (MOH: manufactured by Micro Electronics). Was subjected to microwave heating to obtain a foam.
Next, after heating for 5 minutes in a heating oven set at 180 ° C., the temperature was raised to 360 ° C. over 36 minutes and heated for 30 minutes.
The obtained foam had an expansion ratio of 150 times and a glass transition temperature of polyimide of 400 ° C.
[0043]
Example 1
A heat-fusible polyimide film having a four-layer structure with a protective polyimide film (U-Pirex S: 25 μm) (trade name: U-Pirex VT, manufactured by Ube Industries, Ltd., thickness configuration: 2.5 μm / 20 μm / 2.5 μm) : A total of 25 μm, the glass transition temperature of the heat-fused polyimide: 240 ° C.), the protective polyimide film was peeled off, and a 20 μm stainless steel foil (trade name: SUS304HTA, manufactured by Nippon Steel Corporation) was heated at 340 ° C. by hot pressing. After preheating for 5 minutes, pressing was performed at a pressure of 5 MPa for 1 minute to obtain a laminate.
A mask was placed thereon and stainless steel was etched with a ferrous chloride solution to obtain a substrate having a stainless circuit.
[0044]
A heat-fusible polyimide film having a three-layer structure (trade name: UPILEX VT, manufactured by Ube Industries, Ltd., thickness configuration: 2.5 μm / 20 μm: 2.5 μm in total; (Glass transition temperature: 240 ° C.) A heat-fusible polyimide film and a polyimide foam sheet cut to a thickness of about 10 mm are superimposed and hot pressed at 370 ° C. in a space of 2 mm in thickness. After preheating for 1 minute, pressing was performed for 1 minute at a pressure of 7 MPa to obtain a 2 mm-thick planar heating heater module.
A terminal was taken out from one end of this planar heating heater module, and the pipe was closely covered and subjected to a use test to confirm the adhesion and the temperature control. And the temperature control was very good.
[0045]
【The invention's effect】
According to the present invention, it is possible to obtain a planar heat generating heat module having good adhesion to a heated object, good thermal efficiency and no safety problem.
Further, according to the production method of the present invention, it is possible to produce a planar heating heater module having good adhesion to a heated object, good thermal efficiency, and no safety problem.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a sheet heating heater module.
FIG. 2 is a plan view of an example of the sheet heating heater module of the present invention shown in FIG. 1;
FIG. 3 is a plan view of another example of the sheet heating heater module.
FIG. 4 is a partial schematic view showing an example of application of an example of a planar heat generating heater module of the present invention to a pipe.
[Explanation of symbols]
1 Planar heating heater module
2 Heat-fusible resin film
3 Linear or tape-shaped heating elements
4 Heat-fusible resin film
5 Heat-resistant foam resin insulation
6 pipes

Claims (9)

A linear or tape-shaped heating element is provided between the heat-fusible resin film forming one layer of the laminate and the heat-fusible resin film forming the other layer, insulated from each other, Further, a planar heat generating heat module in which a heat-resistant foamed resin heat insulating material is laminated on at least one side of the heat-fusible resin film. 2. The planar heat-generating heater module according to claim 1, wherein the heat-fusible resin film is a polyimide film having a three-layer structure in which a heat-fusible resin layer is laminated on both sides of a highly heat-resistant polyimide layer. Le. 2. The sheet heating heater module according to claim 1, wherein the tape-shaped heating element is made of stainless steel foil. The planar heat generating heat module according to claim 1, wherein the heat-resistant foamed resin heat insulating material is a foamed polyimide film. 2. The sheet-like heat generating module according to claim 1, wherein all the resins used are made of aromatic polyimide. 2. The sheet-like heat generating module according to claim 1, which can be used at 350 [deg.] C. The planar heat-generating heat module according to claim 1, which has flexibility. The planar heat generating heat module according to claim 1, wherein the heat-fusible resin film comprises a heat-fusible resin having a glass transition temperature lower than the glass transition temperature of the heat-resistant foamed resin heat insulating material. After laminating the heat-fusible resin film and the metal foil, a circuit is formed on the metal foil to form a linear or tape-shaped heating element, and then heat-pressed with the heat-fusible resin film, and at least one side is heat-pressed. A method for producing a planar heat generating heat module in which a heat-resistant foamed resin heat insulating material is thermocompressed and laminated on a heat-fusible resin film.

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